Needle of weaving looms



Jun 7, 1938.

R. DEWAS NEEDLE OF WEAVING LOOMS Filed Dec. 29, 1936 ,4 T TOE/VEKS Patented June 7, 1938 NEEDLE F WEAVING LOOMS Raymond Dewas, Amiens, France Application December 29, 1936, Serial No. 118,065 In France December 31, 1936 Claims.

The invention concerns needle weaving looms in which the holding member of the pulling needle consists of a clamp with two branches which are in springy contact the one with the other and 5 cooperating with a releasing blade which does away with the contact between the said branches when the needle emerges from the shed after having inserted the shoot in it.

It has been notedthat with holding members of this type, as the result of an abnormal overtension on the thread unwinding from a bobbin 7 or coming from any other source of supply, it happens that the end of this thread, caught between the two branches of the springy clamp, slides between the contacting surfaces of the said branches and escapes from them, which produces objectionable results, such for example, as irregularities in the selvedges or in the fabrics themselves.

To overcome these objections the strength of the grip of the holding member of the said pulling needles may be increased, but in this case other difiiculties appear.

The object of the invention is to obviate these objections and it is based on the idea of causing the strength of the grip exerted on the end of the thread caught between the branches of the springy clamp to increase automatically each time that an abnormal increase occurs in the tension of the said thread as it unwinds, and

that, as function of the said increase, by employing for this purpose the action itself of the abnormal increase in the tension of the thread, for operating on the springy branch of the said clamp in such a way as thereby to increase the pressure proportionately against the other branch.

For this purpose the invention consists in providing means on one or on thetwo branches of the said springy clamp, which allow the thread coming from the bobbin and seized in the clamp to come into contact with the outer surface of the springy branch, the said means further being such that they do not prevent the passage of the releasing blade.

In order to. make the invention clearly understood and by way of examples of realization, forms of execution are described below and shown diagrammatically in the attached draw- These forms of execution consist in an application of the invention to pulling needles of the kind described in the U. S. patent application of the applicant Ser. No. 19,576 of May 3, 1935, Needles, the holding member of which consists of a springy clamp with two branches between which the end of the thread presented in the centre of the shed by the conveying needle, is seized when the exchange is made.

Figs. 1 to '7 show one form of execution of a pulling needle effecting the exchange of the thread when the two needles meet, the application of the invention offering, in this case, the advantage of assisting this exchange of the. thread between the said needles.

Fig. 1 is a plan view from above of the clamp which terminates the pulling needle;

Fig. 2 being an elevation;

Fig. 3 is a View incross section on the line 33 of Fig. 2 showing the position of the releasing blade, and

Fig. 4 is an elevation of the face of the needle on the opposite side to that shown in Fig. 2;

Fig. 5 is a plan view from above showing three successive positions of the thread during its exchange, that is to say its passage from the conafter the said pulling needle has begun its return I movement towards the selvedge.

Fig. 8 is a plan view from above similar to Fig. 5; i

Fig. 9 a view similar to Fig. 6;

Fig. 10 an elevation similar to Fig. 7;

Fig. 11 an elevation of the face opposite to that shown in Fig. 10, and

Fig. 12 a View in cross section on the line I2I2 of Fig. 9.

The pulling needle (Figs. 1 to 4) is of the kind described in the above mentioned patent application and is devised with a view to the realization of the invention; the holding mem her for the thread or springy clamp being com posed of two branches, the one 4 rigid and the other 5 flexible.

'2 is the springy clamp of the conveying needle (Fig. 5) in which is caught the end of the weft thread a unwinding from a fixed bobbin and passing over a supporting point 3 integral with the said conveying needle, which allows a stretched part a of the thread a to be presented to the pulling needle which seizes it at'the moa inione of the sides of the tube or of the L-shaped ment'of exchange, in passing between the springy clamp' 2' and the supporting point 3.

1 is a metal part forming the base of the holding member of the pulling needle, on the end of V which it fixed by any appropriate means, for

example by screwswhich, when there is a guard of the kind'shown 'at 20 (Fig. 10), pass through and hold the saidrguard by entering the threaded holes 9 provided in the thicker portion 8 of the part I, the said thicker portion being fitted body in cross section usually forming'the arm-pf;

I the needle and in the guard, so that thispart of ,of the passage'of the releasing blade l6' mounted thetube or L-shaped body is held tightly between I the said part I and the base of the guard 28.

This part 1 is prolonged, being L'-shaped in cross-section, one wing ,4 "constituting the rigid branch of the clamp, whilerthe object of the 'other wing ID will be described below... ii

.On this part- 1 is fixed by screws I one is shaped in such a way 'as to come into contact; over a certain'distance, with the end'of the rigid branch 4, this branch Shaving a notch 6close tofits end on theside facing'theiwingr Ill. .Further the said :part 1 hasza slot at the side to allow at; ,of the flexible branch 5, theopposite end of which 'The thread, continuing to slide between the branches 4 and 5, reaches the level of the notch 6, and as the result of being raised on the edgeiof wing'lll, enters the notch 6 and passes above the point 6'" to take up the position a b At this "moment the thread coming from the bobbin:

presses on the boss 14, thussincreasing the gripping of the part b which, in combination with the, advantage which thenotch 6 affords of limiting "the advance ,of the'thread between the branches 4 and 5, facilitates the removal ofthe thread outside the conveying clamp 2. l t

The needles then stop, afterwards receding to V wards their respective selvedges, so that the a thread a coming from the bobbin and continuing to be raised by the edge of wing l0,,passes above the'point fi'e of 'thenotch, and is finally stretched as shownat 11 '(Figs 6 and 7) the final point of gripping-being at [7 The portiona of the said j' I thread'c'oming from the bobbin, normally presses ,on the boss l3 of the springy'branch S and V on a'support I! situated outside theshedgnear to v pulling needle movesout of' the shedr. I

the .selvedge; the object" of *this blade being to' separate the two branches land Sandthusto release the" end of the weft thread a when l the In: order to compelithe tthread"'to;en'ter.the

notch 6, the ends of thebranch'es arev arranged as follows:' e 7 In plan the end 5' of the flexiblebranch'l'r is slightly raised and straightened'f as shown in Fig. 7 '2) and has, on the side facing thewing' 10, a

Projection l I' cut in" the shape of a heck? 2,

directed (as shown in'FigL '4) 'to'w'ards rthe' rigid H branch 4, in sucha way that,"when pulling taks. place, the threadplacesits'elf easily on the end-5;

' The end' j4''of the rigid branch, [is bevelled across the whole of"itsthicliness as shown-fin Fig.2?

The end of thawing] 0' also" is bevelled and ls" V notched at l0 to'receivethe end of the hook l2 of the -flexible' branch which plane of the said wing; Y e "Finally the ends and 5' of "the branches are 7 extends *in'ithe' cut obliquely as'shownfin' l' 'ig. l. w I V I H In order to ensure a: better gripping of the thread, either at the 'in'om'entiof exchangefiFig.

'5) or at them'oment of pulling (Fig.3); bosses-l3 and M, formed integral with or attached, are

T provided on each Tside' of the notch 6, on the 1 the supporting; point 3 of the conveying needle, approacheslthe pulling needle as 'the'twp needles tliis' means'a't the easement outer face of the flexible branch}? "I'hethread, on leaving the notehffi, 'from the gripping pdint b betweenthe two branches 4fand 5, bears slic cessively on the one andthe' Qwer ye bosses 'Inus arrangedfthe 'holdingfiiezribe'r functions asj folloWs: x f; V It will be seen in Fig; 5 that the portion dfofr the thread, stretched "between-the @clamp and continue to advancetheone towardstl'ie other.

7 lit is" then presented in the p anejpl: contact a of 1 the ends" of the branches" Q *a 'nd'i, between which it'en tersj r f This portion d of thetlirea'dthen s asmid r the h'ook :l'2f0r the flexibl'efbraneh: Slfandfalong' the edge 0': thewing-Hlfarriving even 11y by selectedrin' such away as not to such; a' way'as'to' be }fiush 'with the level of the eventually on its end 5', so' long as the tension of the thread remains normal, that is to say'solong as 'the 'unWinding of the thread fronirits bobbin does not offer any abnormal resistance; 7

' If during the return of the needles over-tension occurs, the portion a of the thread presses more a upon the boss I3 and"e'ventuallyon theendS, which increases proportionally the gripping aw. With'a view to givin'gthe rigid branch '4 the advantages of the flexible branch, a sprin y blade 7 may be fixed onthe inner face of thesaid' rigid branch 4, so as to come'in contact with'the inner 7 face of the springy branch.

To increase the adherence of the thread gripped between theinner surfaces' of thebran'ches and thus to'enable the'said surfacesto offer a greater" resistance to slipping, these surfaces may be,

formed with cavities or notches or the 7 said branches may be pierced, for example as shewn at l8 (Fig. 6) these means however having tobe hinder the free passage of the'releasing'blade.

7 With regard to'Figs. 8 to 12; they Show, a: pull-1 ing needle of the type described in the application for patent mentioned, above also, 'the exchange of the thread with the conveying needle taking place, in this case, wh'eri'the needlesrecede top wards their respective selvedge;

0n the rigid branch I, the wing is decreased in height at a certain" distance from the end,-in

springy branch 5. This fwing lllfitowaridsthe end, is done away within such a way as t'oias'sist in the formation of a'wide lateral notch I0" in the shape of a trapezium (Fig; '11) On ,the opposite side of the and near its raised end 5','the side notch Bis previd'ediwhichisprolonged by a s ot eye et-edge of this 'notch ending in the foifiri of a tooth I'2f,

' the point of which, directed tothe rear, is slightly,

raised Fi'gfl0) the'bos's I 3 beingprovided" onthe outer iaeeiattheendi'o f the slotB' of theflotch fi ber, thus'arrang'ed, of the-pulling needle, oper ates as follows:- r l The portion a of the weft thread, ;stretched between the clamp g and, thegsu pporting point; {I of the conveying needle,

needles (Fig. 8),; 5

ap p s es as. pu ifel It slides- 'tli 'bevlled'eiid a? eftli'agia branch and then meets the sloping side of the trapezoidal part l9 of the springy branch which compels it to pass above its raised end 5' cut obliquely, so as to permit the passage of the Weft thread, and arrives at the moment at which the needles stop in the position shown at a above the branch 5 (Fig. 8).

When the needles return in the direction of their respective selvedge, the portion of the thread at a passes under the raised tooth l2 and is lodged at the bottom of the slot 6.

As the needles continue to recede, the end of the thread slides out of the clamp 2 of the conveying needle and the thread a, coming from the bobbin, passes over the boss 13 and also-owing to the sloping side of the trapezoidal part l9 over the raised end 5.

As the result of the withdrawal of the pulling needle and of the supporting point 3, the definite point of gripping is to be found at 5 (Figs. 9 and the portion a of the weft thread a exercising a pressure on the boss I3 and the end 5'.

If, until the arrival of the drawing needle outside the selvedge, any over-tension occurs, the portion a of the thread presses proportionately more upon the boss l3 and eventually on the end 5' of the springy branch, which proportionately increases the gripping at the point 22 If necessary, to prevent the floating warp threads from entering, on the return of the conveying needle, under the point I2, a guard of the known kind may be used, as shown at With the same object it would be possible to give the branches themselves of the pulling needles of the types above described, the shapes of head which are the subject of the U. S. patents of the applicant, No. 2,053,657 granted September 8, 1936 and No. 2,059,726, granted November 3, 1936.

It is to be understood that, without departing firom the spirit of the invention, alterations, improvements or additions may be made and in the same way the employment of equivalent means may be envisaged; for example, in the first form of execution, the wing l0 could be eliminated and, in this event, the points of the notch 6 would be lowered on the side on the rigid branch or in cavities, so that the thread could enter the said notch; or an equivalent for the wing l0 could be supported by the elastic branch itself.

I claim:

1. In looms of the type having a shed and a pair of reciprocating needles moving toward and away from each other for laying the pick in the shed, a pulling mechanism carried by one of said needles and a conveyor mechanism carried by said other needle, said pulling mechanism comprising a rigid member and a resilient member for gripping the thread therebetween, the gripping end of said flexible member being in resilient contact with said rigid member at least for a portion of its length, gripping means on one of said members for gripping and retaining the thread between said members and cooperating means carried by the gripping ends of said two members for introducing the thread into said gripping means during the reciprocation of the two needles, the gripping end of said flexible member being so constructed and arranged with respect to said rigid member and to said conveyor mechanism that the thread will ride on the exterior surface of said flexible member and exert pressure thereon during the receding movement of said needle whereby the gripping force of said gripping means will be increased by the resistance of the thread during the unwinding operation.

2. In looms of the type having a shed and a pair of reciprocating needles moving toward and away from each other for laying the pick in the shed, a pulling mechanism carried by one of said needles and a conveyor mechanism carried by said other needle, said pulling mechanism comprising a rigid member and. a resilient mem ber for gripping the thread therebetween, the gripping end of said flexible member for at least a portion of said length being in resilient contact with said rigid member, gripping means on one of said flexible members for gripping and retaining the thread between said members during the reciprocating movement and cooperating means carried by the'gripping ends of said two members for introducing the thread into said gripping means during the approaching movement of the two needles, the gripping end of said flexible member being so constructed and arranged with respect to said rigid member and to said conveyor mechanism that the thread will ride on the exterior surface of said flexible member and exert pressure thereon during the receding movement of said needles whereby the gripping force of said gripping means will be increased by the resistance of the thread during the unwinding operation.

3. In looms of the type having a shed and a pair of reciprocating needles moving toward and away from each other for laying the pick in the shed, a pulling mechanism carried by one of said needles and a conveyor mechanism carried by said other needle, said pulling mechanism comprising a rigid member and a resilient member for gripping the thread therebetween, the gripping end of said flexible member being in resilient contact with said rigid member at least for a portion of its length, gripping means carried by said flexible member for gripping and retaining the thread between said two members and cooperating means carried by the gripping ends of said two members for introducing the thread into said gripping means during the receding movement of the two needles, the gripping end of said flexible member being so constructed and arranged with respect to said rigid member and to said conveyor mechanism that the thread will ride on the exterior surface of said flexible member and exert pressure thereon during the receding movement whereby the gripping force of said gripping means Will be'increased by the resistance of the thread during the unwinding operation.

4. In looms of the type having a shed and a pair of reciprocating needles moving toward and away from each other for laying the pick in the shed, a pulling 'mechanism carried by one of said needles and a conveyor mechanism carried by said other needle, said pulling mechanism comprising a rigid member having an L-shaped cross section forming a wing and a flexible member, said flexible member for at least a portion of its length being in resilient contact with said rigid member and notched to receive and retain the thread between said members, the gripping end of said flexible member being slightly raised and straightened and provided with a hook facing said rigid member, and the gripping end of said rigid member and the adjacent end of said wing being bevelled and the said wing being notched to accommodate the hook of said flexible member whereby the thread will be intro- 10 fthread during'the unwinding Operation.

1duced' into; and retained in said notch'during the approaching 'movementof the needle, said pulling mechanism being 'so arrangedwith respect too said conveyorgmechanism that thethread will "ridefon the exterior surface ofjsaid flexible member and exert pressure, thereon during thereced ing' 'movement "of said needles and said flexible nember being embossed on} each side' ofv said notch whereby the gripping force of said gripping means will'beincreased'by the resistance of the 5; In looms of the 't ype'having a shed and a pair of reciprocating needles moving toward and away from each 'other 'forllaying the pick in the she d, a pulling mechanism carried by one of said needles and a conve'yor' mechanism carried'by said other ne'edle; said pulling mechanism com-' prising a. rigid'member andfa resilient member,

said-resilient member; being-'inrresilient contact.

2 for at least a portion of its length with said rigid "2,118, 673 V 7 member and notchedfand provided with a hook facingaway from the gripping end to receive the 7 thread during the receding movement of said needles, the extremity of the gripping end of said flexible jmember being bent outward and pro videdwith a lateral trapezoidal projection-iacing said rigid member and said rigidmember being notched to receive said projection; the end of said ri'gid member facing the conveyor mechanism being bevelled whereby the thread will-slide over the exterior surface of said flexible member J during the approaching movementandwill be ment, and ride overthe exterior; surfaceof-said flexible member and'exertpressu're ontsaid pro= iection whereby the gripping force of said gripping means will be increased-by the resistance of the thread during theunwinding operatioinj' I r RAYMOND IDEWAsreceived in said notch during the receding move V 

